Modern life necessitates carrying and frequent use of variety of documents such as credit cards, identity cards, driving licenses, membership cards and the like. The term “card” will be used herein to describe such documents in general, although some, such as passports and the like may not be shaped like cards. Often, a person holds his important card in a card holder. A typical card holder composed of a series of separate, flat and transparent compartments or pockets which are interconnected either in book- or in strip-form as well as in the shape of a cigarette pack; the card holder is either fixedly connected to the inside of a wallet or is loosely carried in a lady's handbag. These card holders are used for carrying identity cards, credit cards, driver's licenses and similar cards of small size or in folded state, each in one of the transparent or partly transparent pockets, so as to be readily visible and withdrawable for use and/or presentation.
A person carrying a number of such cards is liable to forget returning a card into its appropriate pocket after having used it for payment or for presentation, or the person handed the card may forget to return it to the bearer. It is advantageous to remind the bearer that a specific card is missing from its compartment, by means of a visual or audible signal before the bearer leaves the location where the card was left.
Cardholders having alarm circuitry are described in Israeli Patent No. 68801, U.S. Pat. No. 4,652,865, and U.S. Pat. No. 5,373,283 as having a plurality of flexible pockets wherein conductors are fastened to the inside and outside the pockets and connected to an alarm circuit. Withdrawal of a card from a pocket, and closing the cardholder without returning said card, allows the conductors in that pocket to come into contact, thereby closing an electrical circuit and initiating the alarm circuit. If the electrical circuit is not interrupted, i.e., the card is not returned to the pocket, and the cardholder is closed, the alarm circuit causes an alarm to be emitted. The alarm reminds the owner to retrieve the card and place it back into the empty pocket of the cardholder, thereby opening the closed circuit and terminating the alarm.
U.S. Pat. No. 4,652,865 to Maharshak, titled “Card Holder”, discloses a credit card holder which is composed of a series of transparent pockets and provided with an alarm system warning the owner that a card was not returned into its pocket. Each pocket is provided with two electric contact strips attached to the inside of the pocket walls which are separated by the credit card inside the pocket and are in contact whenever the card is withdrawn. The card holder contains a battery, a buzzer and a timer suitably connected to the contact strips. This timer serves to delay energizing of the buzzer for a time period in which the transaction can be reasonably accomplished, and sounds the alarm only then.
U.S. Pat. No. 5,373,283 to Maharshak, titled “Alarm system for a card holder”, discloses a cardholder with an alarm which includes a control circuit to prevent operation of the alarm until the cardholder is folded up or closed. The control circuit is preferably an interrupted loop of conductive material on the exterior of one or more flexible pockets of the cardholder and a conductive member, which may be part of the loop, on an adjacent pocket or pockets which closes or bridges the gap in the interrupted loop when adjacent pockets are placed into overlying relationship such as by folding the cardholder.
U.S. Pat. No. 7,291,795 to Maharshak, et al., titled “Flexible printed circuits with many tiny holes”, discloses switch or circuit board having a first conductive area on a first side of the board, a second conductive area on a second side of the board, several tiny holes running through the board from the first side to the second side, and a conductive material substantially filling the holes by capillary force, where the conductive material forms an electrical connection between the first conductive area and the second conductive area.